The present invention relates to a spinning apparatus for manufacturing a spun yarn by twisting fibers constituting a sliver leaving a draft device, using a spinning member composed of a nozzle member for generating a whirling current and a non-rotary hollow guide shaft member for spinning.
Spinning devices are known which are composed of a nozzle member for generating a whirling current and a non-rotary hollow guide shaft member having a yarn passing hole and which spin a yarn while causing a whirling current generated by the nozzle member to act on a tip portion of the hollow guide shaft member. In such a spinning apparatus, reversed fibers occur at the tip portion of the hollow guide shaft member and are whirled there by means of the whirling current generated by the nozzle member. Then, the reversed fibers being whirled are wound around a fiber bundle drawn into the yarn passing hole in the hollow guide shaft member, thereby manufacturing a substantially twisted spun yarn.
However, an outer peripheral surface of the tip portion of the hollow guide shaft member and the yarn passing hole thereof are formed such that its cross section perpendicular to an axis of the hollow guide shaft member has a circular (round) cross section, so that the reversed fibers are whirled at substantially constant speed in a circumferential direction of the tip portion of the hollow guide shaft member. When the reversed fibers are thus whirled at the substantially constant speed in the circumferential direction, the reversed fibers are prevented from being disturbed to reduce the amount of hairiness occurring in a spun-out yarn, the surface of which thus feels hard.
It is contemplated that the pressure of compressed air injected from the nozzle member may be reduced to lower the effects of the whirling current on a rear end portion of the reversed fibers to thereby restrain the rear end portion of the reversed fibers from leaving an outer peripheral surface of the tip portion of the hollow guide shaft member, thus increasing the amount of hairiness occurring in the spun-out yarn. When, however, the pressure of the compressed air from the nozzle member is reduced, the strength of the generated spun yarn decreases to increase the yarn breakage rate, thereby reducing spinning efficiency.
The present invention is provided in view of the above problems, and it is an object thereof to solve these problems with the above-mentioned spinning apparatus to generate a spun yarn, the surface of which feels soft without reducing the yarn strength.
To attain this object, the present invention first provides a spinning apparatus comprising a nozzle member for generating a whirling current and a non-rotary hollow guide shaft member having a yarn passing hole so as to execute spinning while causing the whirling current generated by the nozzle member to act on a tip portion of the hollow guide shaft member, wherein a yarn passing hole at the tip portion of the hollow guide shaft member is formed to have a non-circular cross section. This makes it possible to vary a whirling speed of reversed fibers in a circumferential direction. Accordingly, the amount of hairiness occurring in a spun-out yarn increases to enable manufacturing of a soft spun yarn with much hairiness without reducing the strength of the generated spun yarn. Further, this configuration does not require a nozzle pressure (injection pressure) of the nozzle member to be changed, thereby making it possible to maintain an optimal flow rate for spinning. This serves to solve the problem that physical property values of yarns vary depending on the yarn count or the like.
Second, the yarn passing hole at the tip portion of the hollow guide shaft member has a laterally elongate or an elliptic cross section. This makes it possible to smoothly vary the whirling speed of the reversed fibers in the circumferential direction to prevent yarn breakage or the like.
Third, a maximum length of the yarn passing hole formed into a non-circular shape which length starts from the a yarn passing hole inlet located in a tip surface of the hollow guide shaft member equals an average fiber length of fibers constituting a fiber bundle. That is, the yarn passing hole has a non-circular shape over a predetermined length from the yarn passing hole inlet located at the tip surface of the hollow guide shaft member, and this noncircular portion is followed by a circular (round) portion at a downstream side.
The length of the non-circular portion of the yarn passing hole is equal to or smaller than the average fiber length of the fibers constituting the fiber bundle. Consequently, only a portion of the yarn passing hole which is involved in the whirling of the reversed fibers has a non-circular cross section, while a portion that is not involved in the whirling of the reversed fibers has a circular cross section. Therefore, a smooth air current can be maintained through the yarn passing hole in the hollow guide shaft member, thus preventing degradation of the quality of the generated spun yarn.
Fourth, the present invention provides a spinning apparatus comprising a nozzle member for generating a whirling current and a non-rotary hollow guide shaft member having a yarn passing hole so as to execute spinning while whirling reversed fibers at a tip portion of the hollow guide shaft member by means of the whirling current generated by the nozzle member, wherein a restraining section for partly varying a whirling speed of the reversed fibers in a circumferential direction is provided on an outer peripheral surface of the tip portion of the hollow guide shaft member which surface contacts with the reversed fibers. This makes it possible to vary the whirling speed of the reversed fibers in the circumferential direction. Accordingly, the amount of hairiness occurring in a spun-out yarn increases, while wound fibers are restrained from being tightened against the spun yarn, without reducing the strength of the generated spun yarn, thereby enabling manufacturing of a soft spun yarn with much hairiness. Furthermore, a cloth product woven of such spun yarns has a softer feel, and the rotation torque of the yarn decreases, thus allowing the yarn to be more appropriately released and colored during subsequent processes.
Fifth, flat surfaces as the restraining section are formed on the outer peripheral surface of the tip portion of the hollow guide shaft member. This makes it possible to effectively vary the whirling speed of the reversed fibers in the circumferential direction.
Sixth, the flat surfaces as the restraining section are formed at generally equal intervals in the circumferential direction. This makes it possible to effectively vary the whirling speed of the reversed fibers in the circumferential direction.
Seventh, projecting portions or groove portions as the restraining section are formed on the outer peripheral surface of the tip portion of the hollow guide shaft member. This makes it possible to effectively vary the whirling speed of the reversed fibers in the circumferential direction.
Eighth, the present invention provided a spinning apparatus comprising a nozzle member for generating a whirling current and a non-rotary hollow guide shaft member having a yarn passing hole so as to execute spinning while whirling reversed fibers at a tip portion of the hollow guide shaft member by means of the whirling current generated by the nozzle member, wherein an area at the tip portion of the hollow guide shaft member, which an outer peripheral surface shape of area contacts with the reversed fibers, is formed such that its cross section perpendicular to an axis of the hollow guide shaft member is not circular. This makes it possible to vary the whirling speed of the reversed fibers in the circumferential direction. Accordingly, the amount of hairiness occurring in a spun-out yarn increases, while wound fibers are restrained from being tightened against the spun yarn, without reducing the strength of the generated spun yarn, thereby enabling manufacturing of a soft spun yarn with much hairiness. Furthermore, a cloth product woven of such spun yarns has a softer feel, and the rotation torque of the yarn decreases, thus allowing the yarn to be more appropriately released and colored during subsequent processes.
Ninth, the present invention provides a spinning method for executing spinning while whirling reversed fibers at a tip portion of a non-rotary hollow guide shaft member by means of a whirling current acting on the tip portion of the hollow guide shaft member, wherein a whirling speed of the reversed fibers at the tip portion of the hollow guide shaft member is positively varied in a circumferential direction. This increases the amount of hairiness occurring in a spun-out yarn, while restraining tightening of wound fibers against a spun yarn, without reducing the strength of the generated spun yarn, thereby enabling manufacturing of a soft spun yarn with much hairiness. Furthermore, a cloth product woven of such spun yarns has a softer feel, and the rotation torque of the yarn decreases, thus allowing the yarn to be more appropriately released and colored during subsequent processes.
Tenth, the whirling speed is varied by partly restraining whirling of the reversed fibers at the tip portion of the hollow guide shaft member, in the circumferential direction. This makes it possible to effectively vary the whirling speed of the reversed fibers in the circumferential direction.